Oracle Object-Relational add method

I'm learning oracle object-relational model. I already know how to declare, call methods. but how can I add a new method to an existing o开发者_JS百科bject?

is there something like "alter table add function returns xxxxx" ??

thanks

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I think you're looking for the alter type statement: http://www.stanford.edu/dept/itss/docs/oracle/10g/server.101/b10759/statements_4002.htm